Rapamycin Ameliorates Cognitive Impairments and Alzheimer's Disease-Like Pathology with Restoring Mitochondrial Abnormality in the Hippocampus of Streptozotocin-Induced Diabetic Mice.

Alzheimer's disease (AD) and diabetes mellitus (DM) share common pathophysiological findings, in particular, the mammalian target of rapamycin (mTOR) has been strongly implied to link to AD, while it also plays a key role in the insulin signaling pathway. However, the mechanism of how DM and AD is coupled remains elusive. In the present study, we found that streptozotocin (STZ)-induced DM mice significantly increased the levels P-mTOR Ser2448, P-p70S6K Thr389, P-tau Ser356 and Aß levels (Aß oligomer/monomer), as well as the levels of Drp1 and p-Drp1 S616 (mitochondrial fission proteins) are increased, whereas no change was found in the expression of Opa1, Mfn1 and Mfn2 (mitochondrial fusion proteins) compared with control mice. Moreover, the expression of 4-HNE and 8-OHdG showed an aberrant increase in the hippocampus of STZ-induced DM mice that is associated with a decreased capacity of spatial memory and a loss of synapses. Rapamycin, an inhibitor of mTOR, rescued the STZ-induced increases in mTOR/p70S6K activities, tau phosphorylation and Aß levels, as well as mitochondria abnormality and cognitive impairment in mice. These findings imply that rapamycin prevents cognitive impairment and protects hippocampus neurons from AD-like pathology and mitochondrial abnormality, and also that rapamycin treatment could normalize these STZ-induced alterations by decreasing hippocampus mTOR/p70S6K hyperactivity.

Analyzing gully erosion and deposition patterns in loess tableland: Insights from small baseline subset interferometric synthetic aperture radar (SBAS InSAR).

The fragile Loess Plateau of China suffers substantial gully erosion. It is imperative to elucidate gully erosion patterns for implementing effective erosion control strategies. However, high spatiotemporal resolution quantification of gully dynamics remains limited across the Loess Plateau landscape. We utilized the small baseline subset interferometric synthetic aperture radar (SBAS InSAR) technique to investigate the phenomenon of gully erosion and deposition on the Dongzhiyuan tableland, which sits within the vast expanse of the Loess Plateau in China, over the period spanning 2020-2022. The tableland edges subsided while gully bottoms uplifted due to sedimentation. Low elevations underwent active deformation. Slope, aspect, and curvature modulated uplift and subsidence patterns by affecting runoff and sediment transport. Gentle downstream slopes displayed enhanced sedimentation. Southern gullies showed pronounced uplift compared to northern gullies. Heavy rainfall triggered extensive erosion followed by rapid uplift, reflecting an adaptive oscillation between erosion and deposition. Basin hydrology correlated with spatial patterns of deformation. Vegetation cover above 60 % of the maximum substantially increased InSAR error. Our study reveals intricate spatiotemporal behaviors of erosion and deposition in loess gullies using time-series InSAR. The findings provide new insights into gully geomorphology and evolution, and our study quantifies gully erosion and deposition patterns at high spatiotemporal resolution, enabling identification of the most vulnerable areas and prioritization of conservation efforts.

[Determination of N,N'-ethylenediamine disuccinic acid in bioconversion reaction solution using high performance liquid chromatography].

A method was developed for the determination of N,N'-ethylenediamine disuccinic acid (EDDS) in bioconversion samples by high performance liquid chromatography (HPLC). An InertSustain AQ-C18 column (250 mm×4.6 mm, 5 µm) was used in the analysis. The mobile phase was 25% (v/v) methanol with 1.0 g/L Cu(CO2CH3)2·H2O, 2.0 g/L tetrabutylammonium hydroxide, and the pH was adjusted to 2.80 with phosphoric acid. The flow rate of the mobile phase was 1.0 mL/min, and the column temperature was set at 30℃. The detection wavelength was 254 nm. EDDS, fumaric acid, citric acid, malic acid and ethylenediaminetetraacetic acid (EDTA) were separated from one another within 8 min. EDDS showed good linearity in the range of 0.06-0.6 g/L. About 0.25 g/L EDDS was detected in the biosynthesis reaction solution catalyzed by recombinant EDDS-lyase, while 36.56 g/L malic acid was formed as the by-product from fumaric acid. The catalytic activity of the enzyme was confirmed in the hydrolysis of 10 g/L EDDS, which produced 3.05 g/L malic acid in 3 h. This analytical method is simple, rapid, sensitive, reliable, and suitable for the analysis in the research of EDDS bioconversion process.